As one of the richest sources of diversion for the people of Britain between the end of the First World War and the 1960s, the variety theater emerged from the embers of music hall, a vulgar and rumbustious entertainment that had held the working classes in thrall since the 1840s. Music hall bosses decided they would do better business if a man going to theaters on his own could take his wife and children with him, knowing they would see or hear nothing that would scandalize them. So, variety, a gentler, less red-blooded entertainment was gradually established. At the top of the profession...